Field of the Invention and Related Art Statement
The present invention relates to a method of recording an electrophoretic image pattern of various components contained in a biological sample.
In an electrophoresis, a sample such as a serum is applied on a substrate such as a cellulose acetate film by mean of an applicator and is subjected to an electrophoresis in an electrophoretic vessel for a given time. Then the substrate is dyed, decolored and dried successively. Further the substrate is introduced in a densitometer containing a decalin and electrophoretic images are made visible. Then these images are photoelectrically scanned by a light beam.
FIG. 1 is a schematic view showing a principal construction of the densitometer of electrophoretic apparatus. A substrate 1 which has been previously dyed, decolored and dried is fed by feeding rollers 2 into a photometering section 4 containing decalin 3 for making the substrate 1 transparent. The substrate 1 is photometered by the photometer device 5 and then is discharged by means of discharge rollers 6. The photometer device 5 comprises a light source 5a for emitting a light beam and a light receiving element 5b for receiving a light beam transmitted through the substrate 1. The photometer device 5 is moved in a scanning direction b perpendicular to a feeding direction a of the substrate 1 as illustrated in FIG. 2. In this manner electrophoretic images 7 of various components formed on the substrate 1 is photoelectrically scanned to produce a photometered signal.
The photometered signal thus obtained by scanning the electrophoretic images 7 in the densitometer is sampled at a suitable sampling period to derive digital samples. Various measured values of test items e.g. fraction percentages are calculated from the samples thus obtained and these values are printed on a test report by a printer. On the test report, a pattern of the electrophoretic images 7 is also recorded. In case of a serum sample of a human being, an electrophoretic image pattern 14 shown in FIG. 3 is recorded on the test report, said pattern including fraction image 8 of pre-albumin, fraction image 9 of albumin (Alb), fraction image 10 of .alpha..sub.1 -globulin (.alpha..sub.1 -G), fraction image 11 of .alpha..sub.2 -globulin (.alpha..sub.2 -G), fraction image 12 of .beta.-globulin (.beta.-G) and fraction image 13 of .gamma.-globulin (.gamma.-G), these images being successively recorded in the order mentioned above.
In a known method of recording the electrophoretic image pattern 14 on the test report, a predetermined number of samples reckoned from a mechanical scan start point or a point separated from said start point by a predetermined distance are exclusively used to form the pattern 14. Therefore, when the substrate 1 is fed along an inclined path with respect to its longitudinal axis, an electrophoretic image pattern 14B printed on a test report 15B shown in FIG. 4B is shifted in position with respect to an electrohoretic image pattern 14A which is formed on a test report 15A illustrated in FIG. 4A when the substrate 1 is fed along a correct path parallel to its longitudinal axis. Then a necessary part of the pattern might not be printed on the test report. Further, the shift in position of the electrophoretic image patterns on the test reports might hazard the easy and accurate inspection of the electrophoretic image patterns printed on test reports.
In some electrophoretic apparatuses, the electrophoretic time may be varied in order to analyze various samples or to make the process speed adjustable. In such apparatus the sampling period is made longer or shorter when the electrophoretic time is longer or shorter, because a length over which the electrophoretic images are expanded is proportioned to the electrophoretic time. Samples thus obtained are processed in the usual manner, and the measured values and electrophoretic image pattern are printed on a test report card. However, in such apparatuses, since the scanning range and scanning speed in the densitometer are remained constant in regardless to the electrophoretic time, the number of samples obtained by a single scan is varied in accordance with the electrophoretic time. That is to say, the number of samples becomes larger when the electrophoretic time is shorter and the sampling period is shorter. Therefore, when the electrophoretic image pattern is printed on the test report by processing the samples in a usual manner, the electrophoretic image patterns recorded on the test reports are shifted from each other as illustrated in FIGS. 4A and 4B and, in the worst case necessary data might not be recorded.